1. Field
One or more aspects of embodiments of the present disclosure relate to a composite anode active material, a lithium battery including the same, and a method of preparing the composite anode active material.
2. Description of the Related Art
Demands for secondary batteries for use in portable electric devices for information communication, electric bicycles, electric vehicles, and/or the like are rapidly increasing. Examples of such portable electric devices include personal digital assistants (PDAs), mobile phones, and notebook computers. Lithium batteries, and in particular, lithium ion batteries (LIBs) are used as power sources in portable information technology (IT) devices as well as in electric vehicles and for power storage due to their high energy densities and ease of manufacturing. Required properties of LIBs include high energy density and/or long lifespans.
Carbonaceous material, such as graphite, is often used as an anode active material in lithium batteries. However, the use of carbonaceous material such as graphite in high-capacity lithium batteries is limited by its theoretical discharge capacity of about 360 mAh/g.
Lithium-alloyable metal materials such as Si or Sn are attracting attention as anode material alternatives to graphite.
Si has a theoretical capacity of about 4,200 mAh/g. However, when Si is used alone, a volume expansion of about 300% or more may occur during charging and discharging, leading to weak adhesion between the anode current collector and active material, along with a decrease in capacity.
To address this capacity decrease, instead of using a lithium-alloyable metal material such as Si or/and Sn alone, the lithium-alloyable metal material is mixed with a carbonaceous anode active material and/or an alkali metal material to compensate for the anode active material.
However, even when these anode active materials are used, improvements in capacity, lifespan characteristics, and initial efficiency characteristics are often negligible.
Accordingly, there is a need to develop an anode active material with further improved initial efficiency, charge and discharge capacity, and lifespan characteristics, as well as a lithium battery including the anode active material, and a method of preparing the anode active material.
The above information disclosed in this Background section is included only to enhance understanding of the background of the present disclosure, and may therefore may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.